Requirements validation is usually too little and too late.
Historically, the majority of packaged business software implementation methodologies are variations on the waterfall software development lifecycle. The waterfall model is a sequential software development process, in which progress is seen as flowing steadily downwards (like a waterfall) through the phases of planning, requirements, design, development, testing, and go-live. One phase is completed before moving on to the next implementation phase.
A key challenge when using the waterfall approach is requirements management. Simply stated, requirements management is not only requirements gathering but also requirements validation. Missing a requirement or not understanding a requirement's impact during the Requirements phase can be a costly mistake because validation is not completed until the end of the implementation cycle (Testing). This late finding will result in additional rework...